AS VENEZUELA’S political and humanitarian crisis has escalated, the government of Nicolás Maduro made clear that it was prepared to shred what remained of the country’s constitutional order to stop a growing opposition movement. It stripped the opposition-controlled national assembly of its powers, imprisoned several top leaders and tried to slow a campaign to trigger a constitutionally authorized recall referendum on Mr. Maduro. But the opposition drive continued, so last week the regime took definitive action: It formally suspended the referendum process, postponed local and gubernatorial elections, and banned eight senior opposition leaders from leaving the country.

On Sunday, the congress issued a declaration saying Mr. Maduro had staged a coup. That is accurate — and it ought to provoke a consequential reaction from the United States and Venezuela’s Latin American neighbors.

The recall referendum the opposition was pursuing offered a democratic way out of what has become one of the worst political and humanitarian crises in Latin America’s modern history. An oil producer of 30 million people that was once South America’s richest country, Venezuela now suffers from severe shortages of food and medicine, one of the world’s highest murder rates and chronic power shortages, the result of the populist regime’s disastrous economic mismanagement. A new report by Human Rights Watch cites official figures showing a 79 percent increase in maternal mortality this year compared with 2009, and a 45 percent increase in infant mortality compared with 2013. The vast majority of low-income families say they are having trouble obtaining food.

Yet rather than seek humanitarian assistance, the regime denies there is a crisis and punishes health professionals, human rights defenders and ordinary Venezuelans who speak out about the shortages, Human Rights Watch said. The government blames the opposition for what it calls an “economic war,” and it blocks the referendum that might give the country’s angry and hungry people a peaceful outlet. Polls show that about 80 percent would vote to recall Mr. Maduro if they had the chance.

The resort to crude repression may provoke disorder: The opposition has called rallies for Wednesday and appealed to the military not to intervene against them. But the regime may be calculating that it can crush street protests, as it has in the past. What it may fear more is concerted action by its neighbors, such as Brazil and Colombia, as well as by the United States — which under a regional treaty called the Inter-American Democratic Charter have not just the authority but also the duty to isolate and punish the regime for its breach of constitutional order.

Until now the Obama administration has offered lip service to a recall referendum while centering its strategy on promoting negotiations between the government and opposition. But the dialogue initiative led by leftist former Spanish prime minister José Luis Rodríguez Zapatero is going nowhere, despite the announcement Monday of another meeting next weekend; Mr. Maduro is simply using it to screen his denial of democracy. The regime won’t change course unless it comes under far greater pressure, from the streets or from external sanctions. If it wishes to head off still greater turmoil in Venezuela, the United States should be coordinating tough international action.